Multiple vulnerabilities have been identified in Mozilla Thunderbird, the most severe of which could allow for arbitrary code execution. Details of the vulnerabilities are as follows:

• An integer overflow vulnerability in the Skia library when allocating memory for edge builders on some systems with at least 8 GB of RAM. (CVE-2018-5095)
• A use-after-free vulnerability can occur while editing events in form elements on a page. (CVE-2018-5096)
• A use-after-free vulnerability can occur during XSL transformations when the source document for the transformation is manipulated by script content during the transformation. (CVE-2018-5097)
• A use-after-free vulnerability can occur when form input elements, focus, and selections are manipulated by script content. (CVE-2018-5098)
• A use-after-free vulnerability can occur when the widget listener is holding strong references to browser objects that have previously been freed. (CVE-2018-5099)
• A use-after-free vulnerability can occur when manipulating HTML media elements with media streams. (CVE-2018-5102)
• A use-after-free vulnerability can occur during mouse event handling due to issues with multiprocess support. (CVE-2018-5103)
• A use-after-free vulnerability can occur during font face manipulation when a font face is freed while still in use. (CVE-2018-5104)
• A URL spoofing vulnerability can occur with right-to-left text aligned left-to-right. (CVE-2018-5117)
• Multiple memory corruption vulnerabilities can occur due to various memory safety bugs. (CVE-2018-5089)

Successful exploitation of the most severe of these vulnerabilities could allow for arbitrary code execution. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.